Re: [PATCH 3/3] kvm mmu: alloc shadow pages with __GFP_ZERO

Marcelo Tosatti
2009-02-18T18:43:20Z

On Wed, Feb 18, 2009 at 02:54:37PM +0100, Joerg Roedel wrote:
> > Adding __GFP_ZERO here will cause us to clear the page twice, which is wasteful.
>
> The assertion which the attached patch removes fails sometimes. Removing
> this assertion is the alternative solution to this problem ;-)
>

From: Joerg Roedel <joerg.roedel@amd.com>
Date: Wed, 18 Feb 2009 14:51:13 +0100
Subject: [PATCH] kvm mmu: remove assertion in kvm_mmu_alloc_page

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Acked-by: Marcelo Tosatti <mtosatti@redhat.com>

---
arch/x86/kvm/mmu.c | 1 -
1 files changed, 0 insertions(+), 1 deletions(-)

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index d93ecec..b226973 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -802,7 +802,6 @@ static struct kvm_mmu_page *kvm_mmu_alloc_page(struct kvm_vcpu *vcpu,
set_page_private(virt_to_page(sp->spt), (unsigned long)sp);
list_add(&sp->link, &vcpu->kvm->arch.active_mmu_pages);
INIT_LIST_HEAD(&sp->oos_link);
- ASSERT(is_empty_shadow_page(sp->spt));
bitmap_zero(sp->slot_bitmap, KVM_MEMORY_SLOTS + KVM_PRIVATE_MEM_SLOTS);
sp->multimapped = 0;
sp->parent_pte = parent_pte;